Path: ...!local-3.nntp.ord.giganews.com!Xl.tags.giganews.com!local-4.nntp.ord.giganews.com!nntp.supernews.com!news.supernews.com.POSTED!not-for-mail NNTP-Posting-Date: Tue, 30 Jul 2024 20:15:59 +0000 From: john larkin Newsgroups: sci.electronics.design Subject: Re: "Sampler??" Date: Tue, 30 Jul 2024 13:15:59 -0700 Message-ID: References: <72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com> User-Agent: ForteAgent/8.00.32.1272 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 76 X-Trace: sv3-biZyIF8I3SObyrUu991T9c46EPoCJaSHaKeHUsaVjOw3aLae/EjrV/rnSJivu+aOzeOTUTj/3mzJsJh!7kIYwYysr3ttsdKFDGTy5TwttV2XRhz3sLdUrD2iix1eBMZbCnRkxVVi2ptCNm6pnRR8K/q4vIkJ!nBNhFg== X-Complaints-To: www.supernews.com/docs/abuse.html X-DMCA-Complaints-To: www.supernews.com/docs/dmca.html X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.40 Bytes: 4581 On Tue, 30 Jul 2024 19:21:28 -0000 (UTC), Cursitor Doom wrote: >On Tue, 30 Jul 2024 10:39:37 -0700, john larkin wrote: > >> On Tue, 30 Jul 2024 08:58:35 -0000 (UTC), Cursitor Doom >> wrote: >> >>>On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote: >>> >>>> On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john >>>> larkin wrote in >>>> <72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>: >>>> >>>>>On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje >>>>>wrote: >>>>> >>>>>>On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>>Cursitor Doom wrote in >>>>>>: >>>>>> >>>>>> >>>>>>>I still can't see where the 'sampling' bit comes into it. >>>>>>>AFAICT, there's are two signals into this thing and one signal out. >>>>>>>The signal from the LHS is passed through a very fast diode which >>>>>>>generates harmonics from that fundamental. The signal from the RHS >>>>>>>is unmodified and mixed with the desired harmonic to give the >>>>>>>necessary output signal which is then filtered to get rid of the >>>>>>>unwanted mixing products. If that's all correct, as I believe it is, >>>>>>>where does any *sampling* come into it? >>>>>> >>>>>>A 'sampler' is fact a non-linear mixer. >>>>> >>>>>In the audio world, a "mixer" is a linear summer. >>>>> >>>>>In RF, a mixer is usually a multiplier, typically a 4-quadrant diode >>>>>thing or a Gilbert cell type circuit. Or a 2-quadrant thing like a >>>>>pentode. Or even a single diode. All do some flavor of multiplying. >>>>> >>>>>Some mixers inherently multiply a signal by a square wave, which >>>>>resembles other multiplier-type things once you lowpass filter the >>>>>output. That's a "synchronous detector", which we usually do in an >>>>>FPGA. >>>>> >>>>>A sampler is a signal multiplier too. >>>>> >>>>>These are all variations on the basic idea of multiplying two signals. >>>> >>>> A the word 'mixer' in RF is not the same as a multiplier,, >>>> Multipliers are like harmonic generating stages say you have a 1 MHz >>>> distorted sine wave and then a second stage tuned at 3 MHz,.. turned >>>> to third harmonic. >>>> >>>> mamamatical speaking RF mixing is indeed multiplication. >>>> >>>> Like Shakepierce once said: >>>> "What's in a name..." CocaCola wihout coke >>> >>>I think in this context, HP is using the term "sampler" to mean >>>something which 'sniffs' a small amount of a signal for testing >>>purposes. Like a few turns of wire around a transmission line will >>>'sniff' a small sample of what's going on in the line. >>>Where I went wrong was rigidly thinking HP meant 'sampling' in the >>>manner a sampling oscilloscope works. That's what threw me. I tend to >>>interpret things very literally. :( >> >> The sampler in the SA schematic is precisely the sort of sampler used in >> a sampling scope. It contains a step-recovery diode impulse generator >> and no doubt some sampling diodes. > >How can you say that when you haven't seen the schematic? If you've been >able to find it online somewhere then kindly post a link to it here. You posted an excerpt from the HP manual where the sampler is described.